(i) Field of the Invention
The invention relates to a capping member for use in sealing a cable end, to a method of sealing an end of a cable and to a sealed cable end.
(ii) Description of the Prior Art
When a communication cable, for example, a telephone cable, is installed a free end of the cable is maintained to accommodate any desired furture extension of the cable and the free end is capped to prevent entry of moisture and foreign matter into the cable.
One accessary for capping a cable end is described in U.S. Pat. No. 3,590,139, George W. Gillemot, issued June 29, 1971. The accessory of Gillemot has a main body which is tubular and closed at one end, the other end having integral tangs spaced about the periphery of the main body. The tubular body is telescoped over a cable end, the tangs are deflected into contact with the cable surface and are secured thereto with tape. The tubular body is disposed in an upright position and fluid potting compound is introduced into the upright body through the openings provided between the lateral edges of the tangs. The tubular body is suitably made transparent and the assembly is shaken to dislodge trapped air bubbles, during the introduction of the potting compound. the air bubbles being visible through the transparent wall of the body.
The Gillemot construction has several disadvantages outlined below.
Gillemot requires vertical positioning of the accessory for filling with potting compound, with the closed end of the accessory being in a lowermost position, and with good access to the openings defined between the tangs. In many cases these requirements are difficult and costly to achieve, particularly in the case of underground cable, and when, as is usual, a significant length of free cable end, typically more than one meter, is maintained, to allow for future extensions of the cable.
The requirement for transparency whereby air bubbles can be observed, severely restricts the polymer materials which can be employed to fabricate the accessory, and increases the cost since fillers cannot be used to reduce the amount of polymer material.
The need to rely on visual examination to locate air bubbles is unsatisfactory, particularly in that fine bubbles may not be observed, and air bubbles which are trapped between individual conductors of the cable, or between individual conductors and the cable sheathing, will not be observed.
Gillemot requires a significant spacing between adjacent tangs to provide large openings for the flow introduction of the potting compound into the accessory, this is especially apparent from FIG. 3 of the Gillemot U.S. Patent. In addition no means of closing these large openings is provided.
Probably the most serious disadvantage of Gillemot is that the flow introduction of potting compound under gravity, into the upright accessory is inadequate for access of the potting compound to all of the void space defined between the cable end and the accessory, and within the cable end and thus air pockets which may house moisture are maintained.
It is an object of this invention to provide a capping member for use in sealing a cable end which overcomes the afore-mentioned disadvantages.
It is a further object of this invention to provide a method of sealing a cable end which overcomes the afore-mentioned disadvantages.